ef896a9ff7b5678dd586a487ec1ff9222ceefb2d
[melted] / src / modules / core / transition_composite.c
1 /*
2 * transition_composite.c -- compose one image over another using alpha channel
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Dan Dennedy <dan@dennedy.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 */
20
21 #include "transition_composite.h"
22 #include <framework/mlt_frame.h>
23
24 #include <stdio.h>
25 #include <stdlib.h>
26
27 /** Composition class.
28 */
29
30 typedef struct
31 {
32 struct mlt_transition_s parent;
33 }
34 transition_composite;
35
36 /** Get the image.
37 */
38
39 static int transition_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
40 {
41 // Get the properties of the a frame
42 mlt_properties a_props = mlt_frame_properties( this );
43
44 // Get the b frame from the stack
45 mlt_frame b_frame = mlt_frame_pop_frame( this );
46
47 if ( b_frame != NULL )
48 {
49 // Get the properties of the b frame
50 mlt_properties b_props = mlt_frame_properties( b_frame );
51
52 // Arbitrary composite defaults
53 int x = 0;
54 int y = 0;
55 double mix = 1.0;
56
57 // Override from b frame properties if provided
58 if ( mlt_properties_get( b_props, "x" ) != NULL )
59 x = mlt_properties_get_int( b_props, "x" );
60 if ( mlt_properties_get( b_props, "y" ) != NULL )
61 y = mlt_properties_get_int( b_props, "y" );
62 if ( mlt_properties_get( b_props, "mix" ) != NULL )
63 mix = mlt_properties_get_double( b_props, "mix" );
64
65 // Composite the b_frame on the a_frame
66 mlt_frame_composite_yuv( this, b_frame, x, y, mix );
67
68 // Extract the a_frame image info
69 *width = mlt_properties_get_int( a_props, "width" );
70 *height = mlt_properties_get_int( a_props, "height" );
71 *image = mlt_properties_get_data( a_props, "image", NULL );
72 }
73 else if ( a_props != NULL )
74 {
75 // Extract the a_frame image info
76 *width = mlt_properties_get_int( a_props, "width" );
77 *height = mlt_properties_get_int( a_props, "height" );
78 *image = mlt_properties_get_data( a_props, "image", NULL );
79 }
80
81 return 0;
82 }
83
84 /** Composition transition processing.
85 */
86
87 static mlt_frame composite_process( mlt_transition this, mlt_frame a_frame, mlt_frame b_frame )
88 {
89 mlt_frame_push_get_image( a_frame, transition_get_image );
90 mlt_frame_push_frame( a_frame, b_frame );
91
92 // Propogate the transition properties to the b frame
93 mlt_properties properties = mlt_transition_properties( this );
94 mlt_properties b_props = mlt_frame_properties( b_frame );
95 if ( mlt_properties_get( properties, "x" ) != NULL )
96 mlt_properties_set_int( b_props, "x", mlt_properties_get_int( properties, "x" ) );
97 if ( mlt_properties_get( properties, "y" ) != NULL )
98 mlt_properties_set_int( b_props, "y", mlt_properties_get_int( properties, "y" ) );
99 if ( mlt_properties_get( properties, "mix" ) != NULL )
100 mlt_properties_set_double( b_props, "mix", mlt_properties_get_double( properties, "mix" ) );
101
102 return a_frame;
103 }
104
105 /** Constructor for the filter.
106 */
107
108 mlt_transition transition_composite_init( void *arg )
109 {
110 transition_composite *this = calloc( sizeof( transition_composite ), 1 );
111 if ( this != NULL )
112 {
113 mlt_transition transition = &this->parent;
114 mlt_transition_init( transition, this );
115 transition->process = composite_process;
116 return &this->parent;
117 }
118 return NULL;
119 }
120